Examples for 8th grade - page 3

  1. Axial section
    cone2 Axial section of the cone is equilateral triangle with area 300 m2. Calculate volume of the cone.
  2. Hands
    soviet_watch The clock shows 12 hours. After how many minutes will agle between hour and minute hand 80°? Consider the continuous movement of both hands hours.
  3. River
    kongo_river Calculate how many promiles river Hudson average falls, if on section long 921 km flowing water from 1224 m AMSL to 154 m AMSL.
  4. Circle chord
    circleChord What is the length d of the chord circle of diameter 58 mm, if distance from the center circle is 24 mm?
  5. Clock
    hodiny How many times a day hands on a clock overlap?
  6. Server
    p_pro Calculate how many average minutes a year is the web server is unavailable, the availability is 99.99%.
  7. Pool
    swimming-pool The swimming pool is 4 m wide and 20 m long and 156 cm deep. How many hectoliters of water is in it, if the water is 9 cm below its upper edge.
  8. Cuboid
    cuboid_1 The cuboid has a surface area 3380 cm2, the length of its edges are in the ratio 4:3:1. Calculate the volume of the cuboid.
  9. Bus vs. train
    bus_vs_train Bus started from point A 25 minutes before the train started from the same place. The bus went an average speed of 41 km/h, train 67 km/h. To point B train and bus arrived simultaneously. Calculate time of train journey, if train and bus travelled the.
  10. Tetrahedral pyramid
    jehlanctyrboky What is the surface of a regular tetrahedral (four-sided) pyramid if the base edge a=23 and height v=8?
  11. Triangle SAS
    triangle_iron Calculate area and perimeter of the triangle, if the two sides are 19 cm and 80 cm long and angle them clamped is 90°.
  12. Z9-I-4
    numbers_30 Kate thought a five-digit integer. She wrote the sum of this number and its half at the first line to the workbook. On the second line wrote a total of this number and its one fifth. On the third row she wrote a sum of this number and its one nines. Fi
  13. Is right?
    rtriangle Is triangle with sides 24, 51 and 45 right triangle?
  14. Rectangle
    rectangle_inscribed_circle The rectangle is 28 cm long and 21 cm wide. Determine the radius of the circle circumscribing rectangle.
  15. Square
    square_1 Points A[1,5] and B[-4,-5] are adjacent vertices of the square ABCD. Calculate area of the square ABCD.
  16. Movement
    peleton From the crossing of two perpendicular roads started two cyclists (each at different road). One runs at average speed 18 km/h, the second at average speed 24 km/h. Determine the distance between them after 30 minutes cycling.
  17. Cube diagonal
    cube_diagonal Determine length of the cube diagonal with edge 55 dm.
  18. River
    river From the observatory 18 m high and 26 m from the river bank, river width appears in the visual angle φ = 14°30'. Calculate width of the river.
  19. Scale
    pool_1 Swimming pool is long 110 m and 30 m wide. The plan of the city is shown as a rectangle with area 13200 cm2. What scale is the city plan?
  20. Discount
    pulover Ladies sweater was twice discounted. First by 17%, then by 17% of the new price. Its final price was 72 USD. Determine the original price of sweater.

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